This invention relates to a soft focus lens system for use in photography.
Soft focus lens systems are known to produce unique shooting characteristics, and various types have so far been proposed to fully exploit those characteristics. See, for example, Japanese Kokai Nos. 141223/1977, 50309/1981, 156531/1989, 129308/1980, 112144/1987 and 211712/1989.
In most cases, however, the prior art soft focus lens systems have a nearest distance image magnification (which is hereinafter referred to simply as "image magnification") of no more than about 1/10, so when they are used to photograph small objects such as flowers rather than portraits and scenery, sufficiently good results cannot be attained in closeup shooting. It is true that soft focus lens systems capable of shooting up to an image magnification of about 1/4 are available in the art, but they suffer from the disadvantage of undesirably great amounts of lens advancement since the overall system has to be moved to perform focusing. In addition, the lens barrel used has a complex construction and is not only bulky but also heavy.
As an increasing number of modern cameras are provided with an autofocusing capability, there has been a growing demand for autofocusable soft focus lenses since it is inherently difficult to bring them into focus. An imaging system that partly meets this need has been proposed in Japanese Kokai No. 112114/1987, supra, but this system adopts a complex lens composition and attains an image magnification of no more than about 1/10.